The NR-1 is a nuclear submarine of the U.S Navy. Launched on January 25,1969 and conceived as a
bottom-exploring submarine. It can remain in continuous operation for up to 30 days, hosting
a crew of 11. Power is produced
by two 50HP propulsion motors and 4
ducted thrusters enable the submarine to move in every direction with extreme
precision.

This submarine is ideal for underwater
explorations because it has some unique features like viewing ports for external
observation, exterior light sources (supporting TV cameras), an object recovery
claw, a manipulator arm for various gripping and cutting tools and a basket to
place objects recovered from the sea bottom.2 retractable bottoming wheels give
the vessel a special crawling capability. Due to its size and slow surface speed, the
NR-1 is usually towed by its support vessel, the SSVCarolyn
Chouest(a civilian ship).

Left: The NR-1 and the
Carolyn Chouest. Right:The control station inside the
NR-1.

The control station of the
NR-1 is
very similar to a plane's cockpit and from there the crew can video monitor the
sea bottom and the submarine's system status. The photo/video equipment of the
NR-1 consists of low light B/W video cameras, a color camera, a digital
electronic still camera and 2 underwater 35mm still cameras. Advanced electronic
equipment is also used for navigation (target location, data management, Obstacle
Avoidance Sonar).

Although NR-1 has been used for military
and scientific missions over the last 30 years, it gained unexpected popularity
from Dr. Ballard's expeditions to the Titanic. Dr. Ballard operates the
submarine in tandem with JASON, the ROV (Remote Operated Vehicle) of the
Woods Hole Oceanographic Institution.NR-1 was used for Dr. Ballard's exploration
of the Britannic in 1995 but operating with another ROV, the Voyager, which
carried a 3D video camera system developed by NASA.

The
DR1002 is a two-person mini
submersible. An acrylic sphere hosts the control panel and enables the operators
to have a very comfortable accommodation and an almost 360° view, something very
important in underwater exploration. It's also equipped with a pair of
manipulators with audio tactile sensors. Video/photo cameras and lighting can
also be added for broadcasting high quality images from the sea
bottom.

The DR1002 before a dive.

Two of these subs were deployed
for the exploration of the Britannic (during Dr. Ballard's
expedition) allowing Dr. Paul Matthias to test his side-scan sonar before using it
on the Titanic in order to detect the real entity of the damage caused by the
collision with the iceberg. A DR1002 transported the device over Britannic's
wreck.

The "diving saucer"
was one of the most successful manned submersibles ever used for the exploration
of the seas. It was built by Westinghouse for O.F.R.S (Office Francais de
Recherches Sous-Marine) and Jacques Yves Cousteau, after a design of the
French oceanographer. The first drawings were made in 1955.The first test with
the pressure hull took place in 1957 but the prototype (named SP-300)
broke its ropes and sunk to 3280ft (1000m) without damage. After this loss, a
second pressure hull was built (later renamed SP-350 or Denise). The first test of the
SP-350 took place in 1959 and the first operational trials
began in 1960. From 1959 up to 1970 the SP-350 made about 750 dives (2000
dive hours).

The pressure hull was made of mild steel and it was 10,75 in
(19 mm) thick, with a maximum diameter of 6,5 ft and a minimum
diameter of 4,9 ft. There were three 128mm windows and a 15,75 in.
hatch. The submersible could host two crew members in prone position for 4 hours
(max. 24hours).The SP-350 was powered by a centrifugal water pump of 1-2
HP and a maneuvering control was taken by two jets which could be rotated
up to 270 degrees. Buoyancy control was achieved by an internal ballast tank of 55lt and a mercury trim system. The emergency features consisted of 300 lbs of
releasable mercury,400 lbs of releasable emergency weight and an
inflatable conning tower. Electrical power was produced by six lead-acid
batteries (105 amp/hr each).

Left:
The diving saucer during tests at the Naval Ocean Systems Center (NOSC) of the
US Navy.

Right:An underwater shot of the SP-350.

During the first expedition tothe Britannic in
1976, Jacques Cousteau used the SP-350 for the exploration of the debris field. There were some "special"
passengers who also took a dive with the submersible in order to see the sunken liner:William Tantum (then president of the Titanic Historical Society), Sheila Macbeth Mitchell(a survivor who had served as a nurse on the
ship) and Mikis Theodorakis (a famous Greek composer).

This
twin-seat submersible was built by the French company COMEX for the Greek
National Centre of Marine Research (NCMR). It is quite similar to the DR1002
with a large acrylic sphere hosting the pilot and an observer. The Remora
2000 is also described as a "sub-sea helicopter" due to the exceptional
performance of her five thrusters (hosted in 450 mm diameter nozzles) and to her
computer-controlled hydraulic propulsion system. The latter is an evolved
electronic system which controls all the parameters of navigation and is also
responsible for the energy management. The submersible has a very user-friendly
piloting system, through the use of a simple joystick, which enables a
single-hand control of all the important functions needed for diving. Safety
features include a 105kg drop weight and two inflatable "buoyancy collars" that
make the submersible unsinkable, even if the sphere is filled with water.
External lighting consists of four quartz halogen searchlights and two
high-power searchlights.The Remora 2000 is
also fitted with a remote-controlled arm and a complex system of TV cameras and
sonar:

high resolution 725 kHz scanning sonar

scanning profiler

high resolution and sensitivity color video camera

very high sensitivity B/W camera

rear-view color video camera for increased safety
during the exploration of wrecks

video recorder

Left:The research vessel Aegaeo.
Right:The Thetis just before the dive to the Britannic.

The submersible
owned by the NCMR is named Thetis and operates in tandem with the
Centre's research vessel Aegaeo (778tons, 12knots). She hosts 18
scientists and 22 crew and is fitted with modern scientific equipment. The
Thetis dived to the Britannic in 2001 under the command of Kostas
Thoctarides, a well-known commercial diver. The observer was Giorgos
Avgeropoulos , a TV-reporter from the Greek channel ALPHA. The purpose of the
dive was mainly to test some new equipment installed on the submersible but
Avgeropoulos found the chance to film many parts of the wreck. The footage was
broadcasted by ALPHA some days later.